Franciscus Mercurius van Helmont (baptised 20 October 1614 – 1698 or 1699) was a Flemish alchemist and writer, the son of Jan Baptist van Helmont. He is now best known for his publication in the 1640s of his father's pioneer works on chemistry, which link the origins of the science to the study of alchemy. From his early work as a physician, he became a kabbalist and together with Henry More of the Cambridge Platonists he annotated Christian Knorr von Rosenroth's translations of kabbalist texts.